Apparatus for preventing erosion of the seabed in front of hydraulic structures

Abstract

This disclosure relates to an apparatus for preventing erosion of the seabed in front of a lengthy hydraulic structure with a steep face comprising a sheet of rigid or flexible material which is unapertured or perforated, and means for supporting the sheet at an acute angle to the hydraulic structure with an upper edge thereof contiguous the steep face above the seabed and a lower opposite edge portion being remote from the steep face and being positioned adjacent the seabed.

I claim: 
     
       1. The combination of a lengthy hydraulic structure having a steep generally upright uniplanar face, an upper end and a lower end, said lower end being disposed below an upper water level surface of a body of water, a sheet of flexible material, said sheet of flexible material being composed at least of first and second flexible layers, said sheet having upper and lower edge portions, said sheet being disposed at an acute angle to said upright face with said lower edge portion being contiguous a bed of said body of water and said upper edge portion being contiguous said upright face at a point spaced above said bed and below said upper end, said first and second layers including a plurality of perforations, said second layer overlying said first layer, said second layer being taut and said first layer being relatively loose, means for maintaining said sheet of material disposed at said acute angle, and said maintaining means including means for securingsaid upper and lower edge portions to said hydraulic structure and said bed, respectively. 
     
     
       2. The combination as defined in claim 1 including a plurality of beams underlyingly supporting said sheet and extending generally between said structure and said bed. 
     
     
       3. The combination as defined in claim 1 wherein said sheet includes additional layers each having a plurality of perforations, said additional layers being disposed beneath said first layer, said additional layers also being loose, and the looseness of said first and additional layers increases in a direction away from said second layer. 
     
     
       4. The combination as defined in claim 3 including a plurality of beams underlyingly supporting said sheet and extending generally between said structure and said bed. 
     
     
       5. The combination as defined in claim 1 wherein the perforations of said first and second layers are created by constructing said layers from mesh material.